Ethylene-vinyl alcohol copolymer resin composition, ethylene-vinyl alcohol copolymer film formed therefrom, and multilayer structure containing the same

Abstract

The present invention relates to an ethylene-vinyl alcohol copolymer (EVOH) resin composition, an EVOH film formed therefrom, and a multilayer structure containing the same. The core void volume (Vvc) of the surface of the EVOH resin composition is more than 0.010 μm 3 /μm 2 and less than 50 μm 3 /μm 2 ; or its surface pole height (Sxp) is more than 0.010 μm and less than 9.0 μm. The invention can reduce the torque output during processing, reduce the adsorption of fine powder on the surface caused by static electricity generated on the surface of the EVOH, and provide good film thickness uniformity.

What is claimed is: 
     
       1. An ethylene-vinyl alcohol copolymer resin composition in a form of pellet, comprising an ethylene-vinyl alcohol copolymer resin, wherein the ethylene-vinyl alcohol copolymer resin composition has a surface with a core void volume (Vvc) greater than 0.010 μm 3 /μm 2  and less than 50 μm 3 /μm 2 , or a surface pole height (Sxp) more than 0.010 μm and less than 9.0 μm, wherein the ethylene-vinyl alcohol copolymer resin has a saponification degree greater than 99.5 mole %. 
     
     
       2. The ethylene-vinyl alcohol copolymer resin composition of  claim 1  having a moisture content of less than 1 wt %. 
     
     
       3. The ethylene-vinyl alcohol copolymer resin composition of  claim 1 , wherein the ethylene-vinyl alcohol copolymer resin has an ethylene content of 20-48 mole %. 
     
     
       4. The ethylene-vinyl alcohol copolymer resin composition of  claim 2 , wherein the ethylene-vinyl alcohol copolymer resin has an ethylene content of 20-48 mole %. 
     
     
       5. The ethylene-vinyl alcohol copolymer resin composition of  claim 1  having a surface with a maximum line height (Rz) between 0.01 and 9.9 μm. 
     
     
       6. The ethylene-vinyl alcohol copolymer resin composition of  claim 2  having a surface with a maximum line height (Rz) between 0.01 and 9.9 μm. 
     
     
       7. The ethylene-vinyl alcohol copolymer resin composition of  claim 1  having a surface electrostatic voltage of less than 6 kV. 
     
     
       8. The ethylene-vinyl alcohol copolymer resin composition of  claim 2  having a surface electrostatic voltage of less than 6 kV. 
     
     
       9. The ethylene-vinyl alcohol copolymer resin composition of  claim 1  comprising two or more ethylene-vinyl alcohol copolymers with different ethylene contents. 
     
     
       10. The ethylene-vinyl alcohol copolymer resin composition of  claim 2  comprising two or more ethylene-vinyl alcohol copolymers with different ethylene contents.